Animations have become a ubiquitous component of computer-based instruction. Despite their widespread use, however, the evidence concerning their effects on learning is rather ambiguous, suggesting that one needs to have a closer look at the conditions under which animations will aid learning. Accordingly, three sets of moderating variables were identified: (1) the degree of processing support that is used to enhance learning with animation, (2) the context in which the animation is being used (e.g., laboratory setting versus classroom), and (3) the domain that is illustrated by the animation. On the one hand, the studies reported in the current special issue investigate manipulations of these variables. On the other hand, the studies vary among each other with respect to these factors, thereby reflecting the enlarged range of current animation research.